A Short History

Allooy wheels were invented in the States in the 50's, to improve the performance of race cars through their low weight. They were initially built out of an magnesium alloy, but they were too fragile to be used in the streets. They were hard to maintain and, because magnesium has the tendency to oxidate, they had to be laquered too often.
Today these magnesium wheels are still used in F1 racing, in the Indianapolis racing or any other races where they are permanently observed by the support crew.
A different type of alloy was developed for everyday cars. They are made out of an aluminum alloy and are much more resistant to every day use and abuse.
Alloy wheels come in all shapes and sizes, but they all weight less than the steel rims.